Need ID help on this (zoa? or not?)

[MBMtech]

Got these from a tank that was being broken down about a month ago, have started speading on the rock. I have no idea if these are a type of zoanthids or something else. Any assistance in IDing these would be greatly helpful as I like to know what I have in my tank.:bounce3:

 

[Jacwil]

Very common, very fast growers...CAN be invasive. Commonly referred to as yellow polyps

 

[MUCHO REEF]

+1,

Of the Parazoanthus species. Google Parazoanthus Gracilis.


Mucho Reef

 

[Friday Night]

Spread faster than an std in college. Keep an eye on it.
Will take over quick status.